Process of making beryllium oxide



Patented Apr. 30, 1929. I

UNITED STATES 1,710,840 PATENT OFFICE.

EDDIE! 0. PRICE AND HUGH 8. 000233, 01 CLEVELAND, OHIO, ASBIGNOBS, BY IESHEY assremrnu'rs, r naamrux irawroux.

Io Drawing.

The invention is a process of recovering beryllium oxide from ber llium-bearing minera s, 1 such as beryl. e invention contemplates the production of the oxide in. any desired state of purity, andthe production as an'intermediate product of a mixture of beryllium and aluminum oxides which is useful .for many purposes without preliminary separation I oi its com onents. The mixture of oxides just referre to can be obtained practicallyofree from all other substances. I I

Because of its relative abundance, beryl is the preferred raw material, but other beryltions of the process made necessary by the substitution of another mineral for beryl.

erably added to the mixture to promote fusion and expedite the decomposition of the, beryl. Equal weights of beryl and uicklime, or of beryl, lime and calcium uorid, have given excellent results. The mixture is heated to a bright red heat in a clay or gra hite' crucible, and held at this temperature or a short time until it is thoroughly fluid. It is then soured into water, dried, and finely powdere The powdered material is next made into a thin paste with water, and about seven parts by weight of concentrated sulphuric acid is added for each. weight of beryl taken. The mixture is then heated until all water is expelled and fumes of sulphuric acid are evolved freely. .This treatment dehydrates the silica, and converts the metals into sul hates.

"The mass is then extracted thoroughly with several portions of water, the solution being decanted from the silica and undis+ solved calcium sulphate after each extraction. Three or four extractions, if propercally all the beryllium sulphate. All of the aluminum and much of the calcium sulphate will have also dissolved. It is of course undesirable to extract more thorou hly than isnecessary to dissolve the bery ium sulphate, since the amountof calcium sulphate which enters the beryllium solution then needlessly increased.

The extract is concentrated until shows a vdensityof about 1.31 at its bollingpoint.

lium minerals may be used. Any modifica-' heating with lime. Calcium fiuorid is pre ly carried out, will usually dissolve practiture containin beryllium sulfate an alumi traeting the melt with water.

conroaa'rrou or names, a conroiwrron or raocnss or minus nnamrun oxnm Application fled December 18, 1988. Serial Io. 880,548.

The calcium sul hate will then have been practically com etely crystallized from the solution. The ot solution, decanted from the insoluble matter, is further concentrated. to a density of 1.41 and allowed to cool and stand until the aluminum and beryllium sulphates have crystallized out. The mixed sulphates upon being dried and calcined give a mixture of beryllium and aluminum oxides which is quite free from all other materials. Any small amount of iron which ma be present can be removed by treatment wit dilute hydrochloric acid. If her 1 is the raw material, the mixture of oxides o tained will contain about alumina, the rest being ber llium oxide.

e have found that this mixture .of oxides can be separated in a remarkably simple and easy manner by merely fusing it with a'base capable of converting the alumina into an alkali-metal aluininate. Sodium carbonate or hydroxide are suitable. About 3 to 5 parts of the carbonate or hydroxide per part of the mixed oxide is a convenient proportion. The time required to convert the alumina to alumina-te varies somewhat with the manner of calcining the mixed sul hates, but .the separation is usually .compliate in about 1 to 3 hours. The beryllium oxide is unattached during the treatment and is obtained in practically pure form by dissolving the melt and thoroughly washing theinsoluble residue.

We claim: I

1. Process of decomposing beryllium minerals' which comprises heating the mineral with a flux includin a calcium compound, addin sul huric aci to the product so obtaine ,an dehydrating, dissolving the sulphate produced in water, evaporating to a. density of about 1.31, and separating the precipitated calcium sulphate. I

2. rocess of decomposing beryllium minerals which comprises'heatm the mineral with about twice its weight 0 a mixture of 1-1. about equal parts by weight of-quicklime and calcium fluorid.. v

3. Process for the production of beryllium oxide which comprises calcinin a mlxnum sulfate, usingthe resulting oxides of aluminum and beryllium with sodium carbonate for a time sufiicient to convert the. aluminum oxide to sodium alumina'te and ex- 11 5 tained, an

4. Process of decomposing beryllium minerals which comprises heating the mineral with a. flux including a calcium compound, adding sul huric acid to the product so obd dehydrating, dissolving the sulphate produced in water, evaporating to a. density of about 1.31, sepnratingothe precipitated calcium sulphate, further concen- A trating the solution to a density of about 1.41 specific gravity and crystallizin beryl- 10 ROBERT 0. PRICE. HUGH s. oooPER. 

